Have an 06 F350SD Diesel with the towing mirrors that is 'new to me'. The mirrors have indicators in the top left corner that seem to indicate they're heated. I've looked at some of the posts here, but don't see anything that really tells me how to determine if these are working properly. The forum posts indicate that they are always on by default. Does that little 'squiggly line - hand' indicator light up to indicate that they are working or is it just an etching in the glass. It would be nice if you could turn this off and on and have an indicator light. I have unused upfitter switches so might have to rewire them to work that way. Would appreciate others info on whether the little symbols in the mirror itself light up.

 

they are constantly on .. let the truck run for a minute and touch them - you'll see

 

Ok. I'll try that today. Thanks for your reply.

I did see info on here about how to wire into the upfitter switches or any other switches you might want to install. Might look into that for the future or just leave well enough alone.

 

ive seen some vehicles with heated mirrors only work if the mirror selection/adjustment **** was in the "neutral/centered" position. you may want to try that as well.

 

Thanks for the additional info. I do have a tendency to leave the button in other than neutral as it seems like I am constantly adjusting the right hand mirror while towing a fifth wheel. I'll make sure it is in neutral before I check the mirrors.

 

I was told they come on anytime the heat is on

 

I have had both vehicles that have a switch to turn them on and those that don't have a switch. My local service advisor told me that the defrosters in the mirrors came on when you had the internal windshield defrosters on. They are nice when you need them, but with the winters here in Idaho, usually I haven't had frost on them unless there was a blowing snow storm, or freezing rain. But when there was, the defrosters worked well, the 8 Or 10 times since my first truck that had them either 1999 or 2001 super duty...

 

They are on when the key is in RUN.